Relationship between land use classification and grass shrimp Palaemonetes spp. population metrics in coastal watersheds

Estuaries in the southeastern USA have experienced increased loading of contaminants from nonpoint source runoff as well as changes in habitat (e.g., loss of wetlands) due to urbanization. These changes may pose significant risks to estuarine fauna, including crustaceans. Several studies have shown relationships between land use classification and levels of stress in estuarine populations. The grass shrimp of the genus Palaemonetes is one of the dominant species found in estuarine tidal creeks, accounting for more than 50 % of all macropelagic fauna. Grass shrimp populations were sampled monthly for 3 years at six estuarine creeks on Kiawah Island, SC. Creek watersheds were estimated using National Aerial Photograph Program color infrared and low-altitude true color aerial photography combined with in situ differentially corrected global positioning system mapping of engineered features. Land classifications delineated included water, marsh, buildings, roads, and lawns. Pairwise comparisons for grass shrimp densities among sites showed significant differences on an annual and seasonal basis. Significant relationships (p?<?0.05) between land class variables and grass shrimp density were identified both annually and seasonally. These findings suggest an influence of land use on Palaemonetes spp. populations.     

Ergonomic evaluation of a new truck seat design: a field study

A postural evaluation of commercial licensed truck drivers was conducted to determine the ergonomic benefits of a truck seat prototype in comparison with an industry standard seat. Twenty commercially licensed truck drivers were recruited to perform a 90-min driving task. Postures were assessed using accelerometers and a backrest and seat pan pressure mapping system. Subjective discomfort measurements were monitored using two questionnaires: ratings of perceived discomfort (RPD) and the automotive seating discomfort questionnaire (ASDQ). Participants reported significantly higher discomfort scores when sitting in the industry standard seat. Participants sat with more lumbar lordosis and assumed a more extended thoracic posture when seated in the prototype. Pairing the gluteal backrest panel with the adjustable seat pan also helped reduce the average sitting pressure on both the seat pan and the backrest. The prototype provided several postural benefits for commercially certified truck drivers, as it did for a young and healthy population.     

Lead from dust and water as exposure sources for children

Data from the Edinburgh Lead Study are used to estimate the respective contributions of water and dust lead to blood lead in 6–9 year old children. Both sources are significantly related to blood lead. An exposure of 100 g/l in kitchen cold water is estimated to be equivalent to 2700 g/g of lead in dust. In this population water is a more important source of lead than dust for the bulk of the population.This paper is also being published in Proceedings of the Conference on Lead in the Home Environment and is one of several selected from SEGH sponsored conferences for simultaneous publication in this journal.     

Techniques for successfully implementing in-situ remediation systems

As the remediation industry rapidly matures, a greater emphasis is placed on providing on-site remedies involving in-situ soil and groundwater technologies. Selecting and implementing cost-effective technologies requires a defined working process focused on integrating the relationship between the design engineer/scientist and the remedial contractor. This article briefly explores various contractual vehicles and their effect on the designer/contractor relationship and identifies preconstruction documents needed to initiate a remedial construction program. A detailed discussion is presented that describes the transition from remedial design to remedial construction and offers practical application of preconstruction, construction, and postconstruction techniques. Preconstruction techniques involve communication processes and procedures designed to reduce installation uncertainty, address constructability issues, promote value engineering alternatives, and reaffirm the project objectives. Construction techniques focus on effective ways to communicate and document problems and solutions encountered during construction activities. Postconstruction techniques describe ways to provide useful information that may have a continued effect on system performance or used to document the achievement of project goals.